1. Field of the Invention
The present invention relates to a display apparatus used for a TV set or the like, and particularly, to a data processing method and device for converting video data into display data, which are suitable for a display apparatus capable of changing the driving condition for a display means.
2. Related Background Art
As display elements used for display apparatuses, elements using an LED array, an electron-emitting element array, an electroluminescence element, an electrochromic element, a plasma light-emitting element, or a liquid crystal element are known. Particularly, a display element using a liquid crystal element is excellent in its ability of reducing weight and size. An active matrix display element or a super twisted nematic (STN) liquid crystal element using a twisted nematic (TN) liquid crystal, a BTN liquid crystal element using a chiral nematic liquid crystal which exhibits two metastable states, and a liquid crystal element using a chiral smectic liquid crystal and called a ferroelectric liquid crystal element or an antiferroelectric liquid crystal element are especially suitable.
In a conventional display apparatus, when the frame frequency of input video data differs from the frame scanning frequency of the display means, the display image may be disturbed. For this reason, an image is displayed by synchronizing the frame frequency of the input video data with the frame scanning frequency of the display element.
However, under poor environmental conditions such as a high temperature and humidity or a low temperature, image data cannot be satisfactorily displayed in some cases. Therefore, the present inventor examined the feasibility of making the driving condition for the display element variable to optimize the display characteristics. As an example, a method of changing the frame scanning frequency of the display element in accordance with the environmental temperature was examined. However, this technique cannot be employed because it causes a difference between the frame frequency of the input video data and the frame scanning frequency of the display means, as described above.